iXBRL accounts software
iXBRL (Inline XBRL) is a web page version of the accounts in which every figure carries a machine-readable tag. HMRC already needs the accounts and tax computation in iXBRL with every CT600, and from 1 April 2028 Companies House accepts accounts only in iXBRL from commercial software. StatutoryAccounts.io's iXBRL output is in preparation; today it exports PDF, Word and Excel.
Key facts
| Companies House | From 1 April 2028 all accounts in iXBRL through commercial software; web and paper services close for accounts |
|---|---|
| HMRC | Accounts and tax computation in iXBRL with the CT600 |
| Taxonomies, Companies House | FRC 2022 to 2026 suites; micro-entity accounts use the FRS 102 entry point |
| Taxonomies, HMRC | FRC taxonomies for the accounts; CT computational taxonomies for the computation |
| File | One self-contained iXBRL file per set of accounts |
| StatutoryAccounts.io | iXBRL output in preparation; PDF, Word and Excel today |
As at 25 October 2026.
What iXBRL is
An iXBRL file is an XHTML document that people read like a normal set of accounts, with each figure and many text items tagged against a taxonomy: the turnover, the balance sheet total, the directors' names, the audit exemption statement. Companies House and HMRC read the tags. For Companies House the file must be a single, well-formed, valid iXBRL document; PDF is not accepted through software filing.
The tags come from the FRC's taxonomies. The 2026 suite has entry points for FRS 102 (which also covers FRS 105 micro-entity accounts), FRS 101, IFRS and charities. Companies House accepts the 2022 to 2026 suites.
Why it matters now
| Date | What changed |
|---|---|
| 6 April 2025 | Higher company size thresholds for financial years beginning on or after this date |
| 1 January 2026 | FRS 102 Periodic Review 2024 applies to periods beginning on or after this date: new revenue model, leases on the balance sheet, more small company notes |
| 31 March 2026 | HMRC's free Company Tax Return service and the joint Companies House and HMRC service closed; Corporation Tax returns now need commercial software |
| 1 April 2026 | HMRC's fixed late filing penalties for Company Tax Returns doubled; main pool writing-down allowance 14% |
| 23 October 2026 | Companies House confirmed software-only filing from 1 April 2028 and paused the profit and loss filing requirement for small and micro companies |
| 1 April 2028 | All companies must file their accounts with commercial software, in iXBRL |
From 1 April 2028 there is no transition period: any accounts filed from that date, including revised accounts, go through commercial software in iXBRL, whether the company files itself or uses an agent. Small companies can still file abridged or filleted accounts.
What to look for in iXBRL software
- Tags generated from the same data as the accounts, so the human-readable figures and the tags cannot differ.
- The latest accepted taxonomy, kept up to date as the FRC publishes new suites.
- Validation before filing, for example against the Companies House test validator.
- For the CT600: the computation tagged to HMRC's CT computational taxonomy as well.
- For filing at Companies House: the software must be accepted by Companies House as a software filer, with a presenter account.
iXBRL in StatutoryAccounts.io
The iXBRL output is being built on the same mapped figures as the PDF, Word and Excel accounts, using the current FRC taxonomy, so that the filing version and the members' version agree. Until it is released, the accounts can be exported as PDF, Word and Excel and filed by other means.
Frequently asked questions
Do small companies need iXBRL accounts?
For HMRC, yes: the accounts filed with the CT600 are in iXBRL for most companies. For Companies House, from 1 April 2028, when all accounts must be filed with software in iXBRL.
Can I convert a PDF of my accounts into iXBRL?
Companies House software filing accepts only a valid iXBRL file, not a PDF. The file has to be tagged against an FRC taxonomy, which is easiest when the software that prepares the accounts also tags them.
Which taxonomy do micro-entity accounts use?
The FRS 102 entry point of the FRC taxonomy, which also covers FRS 105 micro-entity accounts.
Does StatutoryAccounts.io produce iXBRL?
Not yet: the iXBRL output is in preparation. Today the accounts are exported as PDF, Word and Excel.
Sources
- Companies House: update to accounts filing from April 2028 (23 October 2026)
- Companies House: using software to file your company's information
- Companies House: technical interface specifications for Companies House software
- FRC: 2026 UK and Irish digital reporting taxonomies
- HMRC: taxonomies accepted by HMRC
- HMRC: closure of the service to file your company accounts and tax return
Prepare your statutory accounts
Create an account and set up your company from the Companies House register; your first set of accounts is free. The trial balance import and the CT600 are in preparation.
Join the waitlistGeneral information about UK company law and tax, not legal or tax advice. The directors remain responsible for the accounts and returns they approve and file.